Manufacturing process for large-diameter thick-wall high-strength welded tube

The invention discloses a manufacturing process for a large-diameter thick-wall high-strength welded tube. A high-quality hot-rolled steel plate is adopted as a tube manufacturing raw material. The manufacturing process includes the main steps of plate edge groove machining, forming, high-frequency welding, internal burr removing, submerged arc welding, on-line heat treatment of weld joints, diameter-fixing finishing, straightening, and mark spraying and warehousing. A plate edge groove is a Y-shaped welding groove with the groove angle of 50-60 degrees, and the length range of the blunted edge is 10-20 mm. By means of the adopted technical scheme, a seamless tube is replaced with the large-diameter thick-plate welded tube, and the maximum wall thickness can reach 40 mm; the weldable thickness is increased in the technical scheme compared with singular high-frequency welding, removing of outer burrs generated in high-frequency welding is omitted, and the tube manufacturing procedure is accelerated; and weldin